PLATE CXV 



Skulls of Allops marshi 

 One-fourth natural size. (See pp. 512, 513) 



A, Am. Mus. 1445, paratype, Cheyenne River, S. Dak., Chadron formation. This skull is more brachycephalic than the type, but 



less so than in Brontops dispar. The width across the horns foreshadows Allops crassicornis. The constricted parietal region 

 is characteristic of all the Menodontinae. 



B, Am. Mus. 501, type; South Dakota, probably Cheyenne River Badlands, Chadron formation. The skull is slightly crushed in 



the left side anteriorh-. The canine is compressed anteroposteriorly, the grinding teeth are of moderate width, with marked 

 internal and external cingula. The premolars have deep medifossettes, as in Menodus, and closely resemble those of Allops 

 serotinus. The well-preserved basicranial region shows well the fossa for the internal extension of the interarticular disk and 

 the structures in the region of the periotic. 



